Equation of a Circle Review

Equation of a Circle Review

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Open Ended

What do you remember about the equation of a circle?

Multiple Choice

In the equation (x-3)²+(y+4)²=121, the radius of the circle is

• 242
• 11
• 121
• 22

Multiple Choice

What is the equation of a circle with radius 2 and center (3, 4)?

• (x+3)² + (y+4)² = 2
• (x-3)² + (y-4)² = 2
• (x+3)² + (y+4)² = 4
• (x-3)² + (y-4)² = 4

Multiple Choice

What is the equation of the circle?

• (x+1)² + (y +1)² = 3
• (x+1)² + (y -1)² = 3
• (x+1)² + (y +1)² = 9
• (x-1)² + (y -1)² = 9

Multiple Choice

Which graph corresponds to

x²+ (y-6)²=9

• A

• B

• C

• D

Completing the Square

Why do we sometimes need to complete the square?

Multiple Choice

Convert the to standard form. x² + y² + 6x - 10y - 15 = 0

• (x + 6)² + (y - 10)² = 225

• (x + 3)² + (y - 5)² = 361

• (x + 3)² + (y - 5)² = 7

• (x + 3)² + (y - 5)² = 49

Multiple Choice

What is the center and radius given the equation, x² + y² + 8x - 2y - 64 = 0?

• Center: (-4, 1), Radius: 9

• Center: (4,1), Radius: 8

• Center: (1,-4), Radius: 64

• Center: (-4, 1), Radius: 81